Goodwill by Segment Rollforward (Details) (USD $)	3 Months Ended			3 Months Ended							3 Months Ended							3 Months Ended							3 Months Ended							3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2013 Earn-out Arrangements [Member]		Mar. 31, 2012 Earn-out Arrangements [Member]		Mar. 31, 2013 Reportable Segment [Member] Communications [Member]	Mar. 31, 2012 Reportable Segment [Member] Communications [Member]	Dec. 31, 2011 Reportable Segment [Member] Communications [Member]	Mar. 31, 2013 Reportable Segment [Member] Communications [Member] Earn-out Arrangements [Member]		Mar. 31, 2012 Reportable Segment [Member] Communications [Member] Earn-out Arrangements [Member]		Mar. 31, 2013 Reportable Segment [Member] Electrical Transmission [Member]	Mar. 31, 2012 Reportable Segment [Member] Electrical Transmission [Member]	Dec. 31, 2011 Reportable Segment [Member] Electrical Transmission [Member]	Mar. 31, 2013 Reportable Segment [Member] Electrical Transmission [Member] Earn-out Arrangements [Member]		Mar. 31, 2012 Reportable Segment [Member] Electrical Transmission [Member] Earn-out Arrangements [Member]		Mar. 31, 2013 Reportable Segment [Member] Oil and Gas [Member]	Mar. 31, 2012 Reportable Segment [Member] Oil and Gas [Member]	Dec. 31, 2011 Reportable Segment [Member] Oil and Gas [Member]	Mar. 31, 2013 Reportable Segment [Member] Oil and Gas [Member] Earn-out Arrangements [Member]		Mar. 31, 2012 Reportable Segment [Member] Oil and Gas [Member] Earn-out Arrangements [Member]		Mar. 31, 2013 Reportable Segment [Member] Power Generation and Industrial [Member]	Mar. 31, 2012 Reportable Segment [Member] Power Generation and Industrial [Member]	Dec. 31, 2011 Reportable Segment [Member] Power Generation and Industrial [Member]	Mar. 31, 2013 Reportable Segment [Member] Power Generation and Industrial [Member] Earn-out Arrangements [Member]		Mar. 31, 2012 Reportable Segment [Member] Power Generation and Industrial [Member] Earn-out Arrangements [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 824,707,000	$ 714,800,000	$ 714,800,000					$ 306,800,000	$ 258,000,000	$ 258,000,000					$ 129,500,000	$ 129,500,000	$ 129,500,000					$ 270,800,000	$ 209,700,000	$ 209,700,000					$ 117,600,000	$ 117,600,000	$ 117,600,000
Accruals of acquisition-related contingent consideration				0	[1]	0	[1]				0	[1]	0	[1]				0	[1]	0	[1]				0	[1]	0	[1]				0	[1]	0	[1]
Currency translation adjustments, goodwill	(700,000)							0							0							(700,000)							0
Goodwill, ending balance	$ 824,014,000	$ 714,800,000	$ 714,800,000					$ 306,800,000	$ 258,000,000	$ 258,000,000					$ 129,500,000	$ 129,500,000	$ 129,500,000					$ 270,100,000	$ 209,700,000	$ 209,700,000					$ 117,600,000	$ 117,600,000	$ 117,600,000

[1] Represents contingent consideration for acquisitions prior to January 1, 2009, which is only accrued as earned, in accordance with U.S. GAAP.